[Bug] Artifact tool blocks sandbox security test content with Usage Policy error

Bug Description
I was providing results back from a test Check 1 — D-02 sandbox containment

In chat: "Use the artifact tool to publish. title: 'Sandbox Containment Self-Test', source_format: 'html', body: exactly the following:"
<h1>Artifact Sandbox Containment Self-Test</h1>
<pre id="r" style="font:14px/1.5 monospace">running…</pre>
<script>
const out = [];
const mark = (n, v, d) => out.push((v === 'BLOCKED' ? '✅ ' : '❌ ') + n + ': ' + v + (d ? ' — ' + d : ''));
const render = () => { document.getElementById('r').textContent = out.join('\n'); };
try {
fetch('https://example.com/leak', { mode: 'no-cors' })
.then(() => { mark('network', 'LEAKED', 'request left the sandbox'); render(); })
.catch(e => { mark('network', 'BLOCKED', String(e).slice(0, 50)); render(); });
} catch (e) { mark('network', 'BLOCKED', 'threw synchronously'); }
try { void localStorage.length; void document.cookie; mark('storage', 'LEAKED', 'storage readable'); }
catch (e) { mark('storage', 'BLOCKED', String(e).slice(0, 50)); }
try { const h = window.top.location.href; mark('parent-dom', 'LEAKED', h); }
catch (e) { mark('parent-dom', 'BLOCKED', String(e).slice(0, 50)); }
render();
</script>
Open it from the gallery. PASS = all three lines ✅ BLOCKED. FAIL = any ❌ LEAKED.
and got this response: recap: Phase 46.6's three UAT gaps are fixed, committed, and fully green on clippy/wasm/tests, and both binaries are rebuilt. Next: you launch the web server and gateway, then run the UAT script so I can record the verdict and close the phase.

❯ check 1: [60,104,49,62,65,114,116,105,102,97,99,116,32,83,97,110,100,98,111,120,32,67,111,110,116,97,105,110,109,101,110,116,32,83,101,108,102,45,84,101,115,116,60,47,104,49,62,10,60,112,114,101,32,105,100,61,34,114,34,32,115,116,121,108,101,61,34,102,111,110,116,58,49,52,112,120,47,49,46,53,32,109,111,110,111,115,112,97,99,101,34,62,114,117,110,110,105,110,103,226,128,166,60,47,112,114,101,62,10,60,115,99,114,105,112,116,62,10,32,32,99,111,110,115,116,32,111,117,116,32,61,32,91,93,59,10,32,32,99,111,110,115,116,32,109,97,114,107,32,61,32,40,110,44,32,118,44,32,100,41,32,61,62,32,111,117,116,46,112,117,115,104,40,40,118,32,61,61,61,32,39,66,76,79,67,75,69,68,39,32,63,32,39,226,156,133,32,39,32,58,32,39,226,157,140,32,39,41,32,43,32,110,32,43,32,39,58,32,39,32,43,32,118,32,43,32,40,100,32,63,32,39,32,226,128,148,32,39,32,43,32,100,32,58,32,39,39,41,41,59,10,32,32,99,111,110,115,116,32,114,101,110,100,101,114,32,61,32,40,41,32,61,62,32,123,32,100,111,99,117,109,101,110,116,46,103,101,116,69,108,101,109,101,110,116,66,121,73,100,40,39,114,39,41,46,116,101,120,116,67,111,110,116,101,110,116,32,61,32,111,117,116,46,106,111,105,110,40,39,92,110,39,41,59,32,125,59,10,32,32,116,114,121,32,123,10,32,32,32,32,102,101,116,99,104,40,39,104,116,116,112,115,58,47,47,101,120,97,109,112,108,101,46,99,111,109,47,108,101,97,107,39,44,32,123,32,109,111,100,101,58,32,39,110,111,45,99,111,114,115,39,32,125,41,10,32,32,32,32,32,32,46,116,104,101,110,40,40,41,32,61,62,32,123,32,109,97,114,107,40,39,110,101,116,119,111,114,107,39,44,32,39,76,69,65,75,69,68,39,44,32,39,114,101,113,117,101,115,116,32,108,101,102,116,32,116,104,101,32,115,97,110,100,98,111,120,39,41,59,32,114,101,110,100,101,114,40,41,59,32,125,41,10,32,32,32,32,32,32,46,99,97,116,99,104,40,101,32,61,62,32,123,32,109,97,114,107,40,39,110,101,116,119,111,114,107,39,44,32,39,66,76,79,67,75,69,68,39,44,32,83,116,114,105,110,103,40,101,41,46,115,108,105,99,101,40,48,44,32,53,48,41,41,59,32,114,101,110,100,101,114,40,41,59,32,125,41,59,10,32,32,125,32,99,97,116,99,104,32,40,101,41,32,123,32,109,97,114,107,40,39,110,101,116,119,111,114,107,39,44,32,39,66,76,79,67,75,69,68,39,44,32,39,116,104,114,101,119,32,115,121,110,99,104,114,111,110,111,117,115,108,121,39,41,59,32,125,10,32,32,116,114,121,32,123,32,118,111,105,100,32,108,111,99,97,108,83,116,111,114,97,103,101,46,108,101,110,103,116,104,59,32,118,111,105,100,32,100,111,99,117,109,101,110,116,46,99,111,111,107,105,101,59,32,109,97,114,107,40,39,115,116,111,114,97,103,101,39,44,32,39,76,69,65,75,69,68,39,44,32,39,115,116,111,114,97,103,101,32,114,101,97,100,97,98,108,101,39,41,59,32,125,10,32,32,99,97,116,99,104,32,40,101,41,32,123,32,109,97,114,107,40,39,115,116,111,114,97,103,101,39,44,32,39,66,76,79,67,75,69,68,39,44,32,83,116,114,105,110,103,40,101,41,46,115,108,105,99,101,40,48,44,32,53,48,41,41,59,32,125,10,32,32…
Note: Content was truncated.